1. Field of the Invention
The present invention relates to a control device having a rotary steering device. The present invention also relates to a control device of an endoscope which has a rotary steering device for steering the distal end of an endoscope, and a locking device for locking the rotary steering device to lock the distal end of the endoscope.
2. Description of the Related Art
A typical endoscope is generally provided with an insertion portion which is inserted into a hollow organ or part such as an body cavity or an inner part of a jet engine, and a rotary steering device for steering the distal end of the endoscope to adjust the distal end to a desired curved shape, i.e., to adjust the orientation of the tip of the distal end. Manually turning an angle knob (a control knob) provided on the control body of the endoscope about a stationary rotational shaft causes the distal end of the insertion portion of the endoscope to bend in right and left or upward and downward via a control wire having a distal portion anchored to the distal end of the insertion portion of the endoscope. In general, the endoscope is provided with a locking device for locking the angle knob to lock the distal end of the endoscope to maintain the desired curved shape thereof. This locking device is operated by manually operating a lock knob which is rotatably provided about the aforementioned rotational shaft. Such a locking device is known in the art in the form of a friction locking device which includes a friction pad provided on the lock knob side and another friction pad provided on the angle knob side, wherein the friction pad provided on the lock knob side moves toward and away from the friction pad provided on the angle knob side, in a direction of the axis of the aforementioned rotational shaft, by rotation of the lock knob, and wherein the friction pad provided on the angle knob side rotates together with the angle knob by rotation of the angle knob. In this locking device, if the lock knob is turned in a predetermined rotational direction, the friction pad provided on the lock knob side moves toward the friction pad provided on the angle knob side while rotating about the rotational shaft together with the lock knob via a screw mechanism and eventually comes into contact with the friction pad provided on the angle knob side. Further rotational movement of the lock knob in the same rotational direction causes the friction pad provided on the lock knob side to come into pressing contact firmly with the friction pad provided on the angle knob side to thereby lock the angle knob by friction resistance generated between the friction pad provided on the lock knob side and the friction pad provided on the angle knob side. With the frictional locking device having such structure, the angle knob is prevented from rotating unintentionally, which prevents the distal end of the endoscope from moving unintentionally.
One problem which resides in the endoscope having such a frictional locking device, is that the rotation of the friction provided on the lock knob side pad may be transmitted slightly to the angle knob via the friction pad provided on the angle knob side, causing the shape of the distal end of the endoscope to change slightly since the friction pad provided on the lock knob side comes into pressing contact with the friction pad provided on the angle knob side while rotating about the aforementioned rotational shaft when the lock knob is turned to lock the angle knob. As a result, the distal end of the endoscope may be locked to an undesired curved shape with the frictional locking device.
Endoscopes provided with a plurality of angle knobs for steering the distal end of the endoscope are known in the art. For instance, an endoscope having two angle knobs is known. In this endoscope, the distal end of the endoscope swings in two directions perpendicular to each other by operating the two angle knobs, respectively, via a pair of control wires having respective distal portions anchored to the distal end of the endoscope. Therefore, the distal end of the endoscope can be freely deflected right, left, upward and downward by operating the two angle knobs.
However, in such a conventional type of endoscope, in the case where the above described frictional locking device is provided for each of the two angle knobs, there is a possibility that the operational force of the frictional locking device given to one of the two angle knobs exerts an adverse effect on the operability of the other angle knob. For instance, in the case where the two angle knobs are coaxially arranged adjacent to each other and where the frictional locking device is structured so that one of the two angle knobs is locked by a pressing force toward the other angle knob, this pressing force may have an adverse effect on the other angle knob that does not have to be locked to thereby deteriorate the operability of the other angle knob that needs to be manually rotatable freely and smoothly.
A rotary control member such as a knob or a lever is widely used as a control member for adjusting or locking the distal end of an endoscope, i.e., as an element of the aforementioned steering device or the aforementioned locking device. Generally, such a rotary control member is held rotatably via a retaining mechanism for preventing the rotary control member from coming off a control center shaft (a rotational shaft) in an axial direction thereof. Further, such a rotary control member used for locking the distal end of an endoscope is often provided with a rotational-position control mechanism for making the rotary control member stop with a click at each of the lock and unlock positions thereof. Providing the endoscope with such a rotational-position control mechanism together with the aforementioned retaining mechanism tends to complicate the mechanical structure of the endoscope around the rotary control member thereof.
The aforementioned retaining mechanism is known in the art in the form of a mechanism having a retaining ring which is fitted in an annular groove formed around one end of the control center shaft. In this retaining mechanism, although there is play between the retaining ring and the control center shaft in radial directions perpendicular to the axial direction of the control center shaft, the control center shaft preferably does not rattle due to the play with the retaining ring being engaged with the control center shaft in place. This is true not only for the steering device for steering the distal end of an endoscope but also for any other similar steering devices having a rotary control member corresponding to the aforementioned rotary control member in mechanical apparatuses other than endoscopic apparatuses.
The aforementioned friction pad provided on the lock knob of the locking device is known in the art in the form of a doughnut-shaped disk pad 114xe2x80x2 made of cork or rubber such as shown in FIG. 33. The disk pad 114xe2x80x2 having such a doughnut shape is not easily deformed by external forces applied thereto. Namely, the doughnut shape resists crushing and thus provides stability to the shape of the disk pad 114xe2x80x2. Due to such characteristics of the disk pad 114xe2x80x2, in the locking device using the disk pad 114xe2x80x2, the amount of movement of the disk pad 114xe2x80x2 is generally small in the axial direction of the aforementioned rotational shaft between a point at which the disk pad 114xe2x80x2 is barely in contact with the aforementioned friction pad provided on the angle knob side and another point at which the disk pad 114xe2x80x2 comes in pressing contact firmly with the friction pad to generate a sufficient friction resistance between the disk pad and the friction pad to lock the associated angle knob. Furthermore, this locking operation using the lock knob tends to require great force for turning the lock knob manually.
Therefore, when the lock knob is turned manually, the locking force varies significantly even if the amount of rotation of the lock knob is small, so that a fine adjustment of the locking force is required. Namely, a fine adjustment of the size of a gap between the friction element fixed relative to the lock knob and the friction pad fixed relative to the angle knob is required. Accordingly, it is necessary to adjust the locking force.
However, conventionally, in order to adjust the locking force, the steering device of the endoscope needs to be disassembled, which is troublesome and time-consuming. Moreover, the steerable distal end of the endoscope cannot be half-locked easily so that the distal end which is bent and locked is unlocked in accordance with the degree of an external force applied to the distal end of the endoscope.
It is an object of the present invention to provide a control device having a steering device for steering the distal end of an endoscope and a locking device for locking the steering device to lock the distal end of the endoscope, wherein the curved shape of the distal end of the endoscope does not change by the operation of a lock knob of the locking device.
It is another object of the present invention to provide a control device having a steering device for steering the distal end of an endoscope and a locking device for locking the steering device to lock the distal end of the endoscope, wherein the distal end of the endoscope bends in two directions perpendicular to each other by operating two angle knobs of the steering device, respectively, and wherein the operational force given to one of the two angle knobs does not exert any adverse effect on the operability of the other angle knob.
It is another object of the present invention to provide a steering device which is provided with a rotary control member (e.g., a knob, lever or similar element) fitted on a shaft and held rotatably about the shaft, wherein the steering device is provided with a simple retaining mechanism for preventing the rotary control member from coming off the shaft, and at the same time, a simple rotational-position control mechanism for making the rotary control member stop with a click at each of the lock and unlock positions thereof.
It is a further object of the present invention to provide a manually rotating device (steering device) which is provided with a rotary control member (e.g., a knob, lever or similar element) fitted on a shaft and held rotatably about the shaft, wherein a retaining ring of the aforementioned retaining mechanism can be held stably relative to the control center shaft with a simple structure.
It is a further object of the present invention to provide a control device having a steering device for steering the distal end of an endoscope and a locking device for locking the steering device to lock the distal end of the endoscope, wherein the locking force by the locking device can be finely adjusted easily without the need of disassembling the steering device.
It is another object of the present invention to provide a control device having a steering device for steering the distal end of an endoscope and a locking device for locking the steering device to lock the distal end of the endoscope, wherein the locking force by the locking device does not have to be adjusted, and at the same time, the distal end of the endoscope can be half-locked easily with the locking device in an easy and quick manner.
Other objects of the invention will become apparent to one skilled in the art in the following disclosure and the appended claims.
To achieve the object mentioned above, according to an aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provide, the endoscope including at least one steering member which is rotated to bend the steerable bendable portion; at least one locking member which is rotated to lock the steering member, the steering member and the locking member being rotated about a common axis; and at least one axially-movable lock member which moves relative to the steering member along the common axis without rotating about the common axis to lock and unlock the steering member when the locking member is turned in a first rotational direction and a second rotational direction, respectively.
Preferably, the endoscope further includes a rotational shaft which supports the locking member in a rotatable manner about an axis of the rotational shaft; and a non-cylindrical portion having a non-circular cross section which is formed on the rotational shaft. The axially-movable lock member is positioned around the non-cylindrical portion in a manner so that the axially-movable lock member can move along the axis of the rotational shaft relative to the non-cylindrical portion without rotating about the axis of the rotational shaft.
In an embodiment, the endoscope further includes a drive force transmitting mechanism via which the axially-movable lock member moves along the axis of the rotational shaft in accordance with rotation of the locking member.
In an embodiment, the endoscope further includes a removable retaining member which is fitted on the non-cylindrical portion in a direction perpendicular to the axis of the rotational shaft. The removable retaining member is prohibited from moving along and rotating about the axis of the rotational shaft relative to the non-cylindrical portion in a state where the removable retaining member is fitted on the non-cylindrical portion. The removable retaining member is engaged with the axially-movable lock member to prohibit the axially-movable lock member from rotating about the axis of the rotational shaft relative to the non-cylindrical portion.
In an embodiment, the endoscope further includes a guide portion, formed on the axially-movable lock member, for preventing the removable retaining member from coming out of the non-cylindrical portion in a state where the guide portion is fitted on the removable retaining member, wherein the guide portion is fitted on the removable retaining member so that the guide portion is movable in a direction of the axis of the rotational shaft without rotating about the axis of the rotational shaft relative to the removable retaining member.
Preferably, the steering member includes a steering knob which is mounted around the rotational shaft, and the non-cylindrical portion is formed on the rotational shaft in an inner space of the steering knob.
In an embodiment, the steering member includes a first steering member which is rotated to bend the steerable bendable portion in a first bending direction; and a second steering member which is rotated to bend the steerable bendable portion in a second bending direction, the first steering member and the second steering member being rotated about the common axis. The locking member includes a first locking member which is rotated to lock the first steering member; and a second locking member which is rotated to lock the second steering member, the first locking member and the second locking member being rotated about the common axis. The axially-movable lock member includes a first axially-movable lock member which moves relative to the first steering member along the common axis without rotating about the common axis to lock and unlock the first steering member when the first locking member is turned in the first rotational direction and the second rotational direction, respectively; and a second axially-movable lock member which moves relative to the second steering member along the common axis without rotating about the common axis to lock and unlock the second steering member when the second locking member is turned in the first rotational direction and the second rotational direction, respectively.
In an embodiment, the endoscope further includes an inner body shaft which is fixed to a body of the endoscope; and an outer cylindrical body which is coaxially provided around the inner body shaft. The first axially-movable lock member is mounted to the to inner body shaft to be movable along an axis of the inner body shaft without rotating about the inner body shaft. The second axially-movable lock member is mounted to the outer cylindrical body to be movable along an axis of the outer cylindrical body without rotating about the outer cylindrical body.
In an embodiment, the first steering member includes a first cylindrical shaft, and the second steering member includes a second cylindrical member which is coaxially fitted on the first cylindrical shaft. The first cylindrical shaft and the second cylindrical member are fitted in a cylindrical space which is provided between the inner body shaft and the outer cylindrical body in a radial direction thereof, the first cylindrical shaft and the second cylindrical member being rotatable relative to each other about the axis of the inner body shaft.
In an embodiment, the first locking member is mounted to the inner body shaft to be rotatable about the axis of the inner body shaft, and the second locking member is mounted to the outer cylindrical body to be rotatable about the axis of the outer cylindrical body.
In an embodiment, the drive force transmitting mechanism includes male and female threads which mesh with each other, the male and female threads being formed on the locking member and the axially-movable lock member, respectively.
In an embodiment, the endoscope further includes at least one axially-immovable lock member which is fixed to the steering member. The axially-movable lock member moves toward the axially-immovable lock member to lock the steering member when the locking member is turned in the first rotational direction.
In an embodiment, the endoscope further includes a first friction pad fixed to the axially-movable lock member; and a second friction pad fixed to the axially-immovable lock member. The axially-movable lock member moves toward the axially-immovable lock member to bring the first friction pad into pressing contact with the second friction pad to thereby lock the steering member when the locking member is turned in the first rotational direction.
In an embodiment, the endoscope further includes an adjusting device for adjusting a position of the axially-immovable lock member relative to the steering member in a direction of the common axis.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including at least one control knob which is manually turned about an axis to bend the steerable bendable portion so as to direct the tip of the steerable bendable portion toward a target part; at least one lock knob which is manually turned about the axis to lock the control knob; and at least one axially-movable lock member which moves relative to the control knob along the axis without rotating about the axis to lock and unlock the control knob when the lock knob is turned in a first rotational direction and a second rotational direction, respectively.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a first steering portion which is rotated to bend the bendable portion in a first bending direction; second steering portion which is rotated to bend the bendable portion in a second bending direction, the first steering portion and the second steering portion being rotated about a common axis; a first axially-movable lock member which moves along the common axis to bias the first steering portion in a first direction away from the second steering portion to lock the first steering portion; and a second axially-movable lock member which moves along the common axis to bias the second steering portion in a second direction away from the first steering portion to lock the second steering portion.
Preferably, the first axially-movable lock member and the second axially-movable lock member move away from each other to bias the first steering portion and the second steering portion, respectively, to lock the first steering portion and the second steering portion, respectively.
In an embodiment, the endoscope further includes a first locking portion which is rotated about the common axis to move the first axially-movable lock member along the common axis toward and away from the first steering portion when the first locking portion is turned in forward and reverse rotational directions thereof; and a second locking portion which is rotated about the common axis to move the second axially-movable lock member along the common axis toward and away from the second steering portion when the second locking portion is turned in forward and reverse rotational directions thereof.
In an embodiment, the first locking portion is engaged with the first axially-movable lock member via first screw threads so that the first axially-movable lock member moves along the common axis, due to an engagement of the first screw threads, when the first locking portion is turned. The second locking portion is engaged with the second axially-movable lock member via second screw threads so that the second axially-movable lock member moves along the common axis, due to an engagement of the second screw threads, when the second locking portion is turned.
Preferably, each of the first axially-movable lock member and the second axially-movable lock member moves along the common axis without rotating about the common axis.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a first steering portion which can be rotated independently to bend the steerable bendable portion in a first bending direction; and a second steering portion which can be rotated independently to bend the steerable bendable portion in a second bending direction, the first steering portion and second steering portion being rotated about a common shaft; at least one axially-movable lock member which moves along an axis of the common shaft toward and away from one of the first steering portion and the second steering portion to one of lock and unlock the one of the first steering portion and the second steering portion. The axially-movable lock member moves along the axis to bias the one of the first steering portion and the second steering portion in a direction away from the other of the first steering portion and the second steering portion when locking the one of the first steering portion and the second steering portion.
In an embodiment, the axially-movable lock member includes a first axially-movable lock member which moves along the axis to bias the first steering portion in a first direction away from the second steering portion to lock the first steering portion; and a second axially-movable lock member which moves along the axis to bias the second steering portion in a second direction away from the first steering portion to lock the second steering portion.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a steering member which is rotated about a shaft to bend the bendable portion; a locking member which is rotated about the shaft to lock the steering member; and a retaining member which is fixed to an end of the shaft to prevent the locking member from coming out of the shaft from the end thereof; and a spring which rotates together with the locking member when the locking member is turned. The locking member includes an engaging portion, wherein the retaining member includes at least one stop portion and at least one stop recess. The spring is engaged with the stop recess with a click when the engaging portion abuts against the stop portion.
In an embodiment, the stop portion and the stop recess are positioned substantially on opposite sides of the shaft in a radial direction thereof.
In an embodiment, the stop portion and the stop recess include two stop portions and two stop recesses, respectively.
In an embodiment, the two stop portions and the two stop recesses are formed on the retaining member at different circumferential positions thereof. One of the two stop portions and one of the two stop recesses are positioned substantially on opposite sides of the shaft in a first radial direction thereof. The other of the two stop portions and the other of the two stop recesses are positioned substantially on opposite sides of the shaft in a second radial direction thereof.
In an embodiment, the spring elastically presses the retaining member in a direction toward an axis of the shaft.
In an embodiment, a non-circular hole is formed on the retaining member, and the end of the shaft is formed to have a cross sectional shape corresponding to the shape of the non-circular hole so that the retaining member can be fitted on the end of the shaft.
In an embodiment, the retaining member is fixed to the end of the shaft via a set screw which is screwed into the end of the shaft to prevent the retaining member from coming out of the end of the shaft.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a steering member which is rotated about a shaft to bend the bendable portion; a locking member which is rotated about the shaft to lock the steering member; a retaining member fixed to an end of the shaft to prevent the locking member from coming out of the shaft from the end thereof; a projection which projects from the locking member; a spring which is fixed to the locking member so that part of the spring elastically presses the retaining member in a direction toward the projection. Part of the spring and the projection are positioned substantially on opposite sides of the shaft in a radial direction thereof. The retaining member includes at least one stop face and at least one stop recess. Part of the spring is engaged with the stop recess with a click when the projection abuts against the stop face.
In an embodiment, the stop face and the stop recess include two stop faces and two stop recesses, respectively.
In an embodiment, the two stop faces and the two stop recesses are formed on the retaining member at different circumferential positions thereof. One of the two stop faces and one of the two stop recesses are positioned substantially on opposite sides of the shaft in a first radial direction thereof. The other of the two stop faces and the other of the two stop recesses are positioned substantially on opposite sides of the shaft in a second radial direction thereof.
According to another aspect of the present invention, a manually rotating device is provided, including a shaft; a manual operation member which is mounted to the shaft to be turned manually about the shaft; a retaining member fixed to an end of the shaft to prevent the manual operation member from coming out of the shaft from the end thereof; and a spring which is associated with the retaining member, wherein the spring rotates together with the manual operation member when the manual operation member is turned. The manual operation member includes an engaging portion, the retaining member includes at least one stop portion and at least one stop recess. The spring is engaged with the stop recess with a click when the engaging portion abuts against the stop portion.
In an embodiment, the stop portion and the stop recess are positioned substantially on opposite sides of the shaft in a radial direction thereof.
According to an aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a hollow steering knob which is manually turned about a shaft to bend the steerable bendable portion, an opening being formed on the steering knob; a first friction brake member which rotates together with the steering knob when the steering knob is turned; a lock operation member which can be manually turned relative to the steering knob; a second friction brake member which is driven to move toward and away from the first friction brake member to lock and unlock the steering knob in accordance with rotation of the lock operation member relative to the steering knob; and a locking force adjusting device for adjusting an initial space between the first friction brake member and the second friction brake member, the locking force adjusting device being accessible from the outside of the endoscope via the opening of the steering knob.
Preferably, the locking force adjusting device moves the first friction brake member relative to the steering knob to adjust the initial space in a direction of an axis of the shaft when the locking force adjusting device is operated via the opening.
In an embodiment, the locking force adjusting device includes first and second thread portions which mesh with each other, the first thread portion being positioned in the steering knob, the second thread portion being formed on the first friction brake member; an at least one engaging portion formed on the first friction brake member to be exposed to the opening. The first friction brake member moves in the direction of the axis of the shaft relative to the steering knob in accordance with the first and second thread portions when the first friction brake member is rotated relative to the steering knob with the at least one engaging portion.
In an embodiment, the steering knob is formed as a substantially hollow cylindrical shape, and is provided with an end face extending substantially perpendicular to the axis of the shaft. The opening is formed at the end face of the steering knob. The second friction brake member and the first friction brake member are positioned in the steering knob in the opening thereof so that an outer surface of each of the second friction brake member and the first friction brake member is substantially flush with the end face of the steering knob.
In an embodiment, the first friction brake member is mounted to the steering knob to be movable in the direction of the axis of the shaft and to be rotatable about the axis of the shaft together with the steering knob. The locking force adjusting device includes a first thread positioned in the steering knob; an adjusting ring having a second thread which meshes with the first thread; and at least one engaging portion formed on the adjusting ring to be exposed to the opening. The first friction brake member moves in the direction of the axis of the shaft relative to the steering knob if the adjusting ring is rotated relative to the steering knob with the engaging portion.
In an embodiment, the steering knob is formed as a substantially hollow cylindrical shape, and is provided with an end face extending substantially perpendicular to the axis of the shaft. The opening is formed on the end face of the steering knob. The second friction brake member and the first friction brake member are positioned in the steering knob in the opening thereof so that an outer surface of each of the second friction brake member, the first friction brake member and the adjusting ring is substantially flush with the end face of the steering knob.
Preferably, the adjusting ring prevents the first friction brake member from moving out of the opening.
In an embodiment, the engaging portion includes at least one hole which is formed on the surface of the first friction brake member which is exposed to the opening.
In an embodiment, the engaging portion includes two holes which are formed on the surface of the first friction brake member, and two pins of a pin face wrench can be engaged in the two holes, respectively.
In an embodiment, the engaging portion includes at least one hole which is formed on that surface of the adjusting ring which is exposed to the opening.
In an embodiment, the engaging portion includes two holes which are formed on the surface of the adjusting ring, and two pins of a pin face wrench can be engaged in the at least two holes, respectively.
In an embodiment, the first friction brake member and the second friction brake member can be mounted to and dismounted from the steering knob via the opening.
In an embodiment, the lock operation member is positioned to face the opening of the steering knob, wherein the locking force adjusting device is accessible from the outside of the endoscope via a portion of the opening to which the lock operation member does not face.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including first and second hollow steering knobs which are manually turned independently of each other about a shaft to bend the bendable portion, wherein the first and second hollow steering knobs are positioned adjacent to each other in a direction of an axis of the shaft; a first opening formed on the first hollow steering knobs; a second opening formed on the second the two hollow steering knobs; a first friction brake member, provided for each of the first and second hollow steering knobs, which rotates together with associated one of the first and second hollow steering knobs when associated one of the first and second hollow steering knobs is turned; a lock operation member, provided for each of the first and second hollow steering knobs, which can be manually turned relative to associated one of the first and second hollow steering knobs; a second friction brake member, provided for each of the first and second hollow steering knobs, which is driven to move toward and away from associated the first friction brake member to lock and unlock associated one of the first and second hollow steering knobs in accordance with rotation of associated the lock operation member relative to the associated hollow steering knob; and a locking force adjusting device for adjusting an initial space between the first friction brake member and the second friction brake member for each of the first and second hollow steering knobs, the locking force adjusting device being accessible from the outside of the endoscope via associated one of the first and second openings. The first and the second openings are formed on the first and second hollow steering knobs to be open in opposite directions so as not to face each other.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a steering device having a first operation member which is manually turned to bend the bendable portion so as to direct the tip of the bendable portion toward a target part; and a locking device having a second operation member which is manually turned to lock the steering device. A first friction member provided on the locking device comes into pressing contact with a second friction member provided on the steering device by an operation of the second operation member. The first friction member is shaped so as to facilitate compression thereof in a direction of the thickness of the first friction member.
In an embodiment, the first friction member includes a plurality of gaps for facilitating compression of the first friction member in the direction.
In an embodiment, the plurality of gaps are formed by a plurality of projections and depressions.
In an embodiment, the first friction member has a general cylindrical shape, and the plurality of projections and depressions extend across the first friction member in radial directions.
In an embodiment, the plurality of gaps includes a plurality of holes.
In an embodiment, the first friction member has a general cylindrical shape, and the plurality of holes extend across the first friction member in radial directions.
In an embodiment, the plurality of projections and depressions are arranged at equi-angular intervals about a center of the first friction member.
In an embodiment, the plurality of holes are arranged at equi-angular intervals about a center of the first friction member.
In an embodiment, the first friction member is formed in a disk shape so as to be compressed in a direction of the thickness of the first friction member easier than in a radial direction of the first friction member.
According to another aspect of the present invention, an endoscope having an elongated insertion portion provided at a distal end thereof with a steerable bendable portion is provided, the endoscope including a steering device having a first operation member which is manually turned about a shaft to bend the bendable portion so as to direct a tip of the bendable portion toward a target part; a locking device having a second operation member which is manually turned about the shaft to lock the steering device; a first friction member which is provided as an element of the locking device which is movable in a direction of an axis of the shaft and does not rotate about the axis; a second friction member which rotates together with the first operation member; and a cam mechanism, elements of which are provided on the second operation member and the first friction member. The first friction member is moved in the direction of the axis of the shaft to come into contact with the second friction member to restrict rotation of the first operation member via the cam mechanism.
In an embodiment, the locking device includes a rotational member which is provided integral with the second operation member; and an axially-movable lock member which is positioned to face the second friction member and is movable in the direction of the axis of the shaft without being rotatable about the axis, the first friction member being fixed to the axially-movable lock member. The cam mechanism includes at least one cam follower fixed to the rotational member; and at least one cam groove which is formed on the axially-movable lock member and in which the cam follower is engaged. Turning the second operation member causes the axially-movable lock member to move in the direction of the axis of the shaft via an engagement of the cam follower and the cam groove so that the first friction member comes into contact with the second friction member to restrict rotation of the first operation member.
In an embodiment, the cam groove includes an inclined groove portion which is inclined with respect to a plane which is perpendicular to the axis of the shaft.
In an embodiment, the axially-movable lock member includes at least one leaf spring portion which can elastically bend with respect to the axially-movable lock member, and an under surface of the leaf spring portion constitutes a part of a cam surface of the cam groove.
Preferably, the leaf spring portion of axially-movable lock member includes a slit, wherein the cam groove connects with an external portion of the axially-movable lock member via the slit.
Preferably, at least one end of the cam groove is formed to be wider than a middle portion of the cam groove.
Preferably, each of opposite ends of the cam groove is formed to have a substantially circular cross section, and a diameter of each of the opposite ends of the cam groove is slightly greater than a diameter of the cam follower.
The present disclosure relates to subject matter contained in the following six Japanese Patent Applications No.2000-117658 (filed on Apr. 19, 2000), No.2000-121994 (filed on Apr. 24, 2000), No.2000-132203 (filed on May 1, 2000), No.2000-170907 (filed on Jun. 7, 2000), No.2000-229088 (filed on Jul. 28, 2000) and No.2000-229089 (filed on Jul. 28, 2000) which are expressly incorporated herein by reference in their entireties.